How to take professional quality photos?

I have a digital nikon it's not fancy or anything

Well you know, you don't need an expensive camera for great photos! What you have is perfect to start with.
i would recommend googling after free photography lessons and learn the basics, learn techniques. Learn how to use photoshop or other photo manipulating software(you will definitely need it).
Join photo-related communities(flickr.com for example) and ask for constructive criticism - you will get it, no doubt about it.

You don't need a professional camera, but it does need to have a certain set of features. Mainly it needs to be an SLR with the ability to change it to full manual control. You need to learn how to use its features (go on a college course or something) and also learn to understand light. The last point is critical. A well lit photograph of average composition will always work better than an excellent composition with poor light.

Biggest step, put time and effort into learning some basics. Additionally in your case, stop thinking a tiny pic of your sunglasses in a car mirror which you've edited nearly to death is a picture good enough to share with the world.

Study, study, study, photography to a professional level,

pro images are made not taken…